This project investigates two fundamental problems in biology: (1) role of dynamic patterns in embryological and evolutionary biology and (2) kinetics of enzymes located in cell membranes. The first area involves a demonstration of the role which simultaneous reaction and diffusion might play in the formation of biological patterns such as those which determine the shape of organs. The second area involves investigation of the effect of diffusion limitation by cell membranes on the kinetics of enzymes contained in them. Digital computer simulation and bifurcation theory are the principal tools of these investigation.